Background: Anticoagulation with vitamin K antagonists reduces major thromboembolic complications in at-risk patients. With portable monitoring devices, patients can conduct their own international normalized ratio testing and dose adjustment at home.

Purpose: To determine whether patient self-testing (PST), alone or in combination with self-adjustment of doses (patient self management [PSM]), is associated with a reduction in thromboembolic complications and all-cause mortality without an increase in major bleeding events compared with usual care.

Conclusion: Compared with usual care, PST with or without PSM is associated with significantly fewer deaths and thromboembolic events, without increased risk for a serious bleeding event, for a highly selected group of motivated adult patients requiring long-term anticoagulation with vitamin K antagonists.